1. Field of the Invention
The present invention relates in general to a heating for facilitating the evaporation of remaining liquid phase refrigerant.
2. Description of the Prior Art
A typical combined liquid receiver and liquid divider (hereinbelow, referred to simply as "the combined liquid receiver and divider") having heat exchanging means therein is disclosed in Japanese Patent Laid-open Publication No. Sho. 50-141744 entitled "a combined liquid receiver and liquid divider having heat exchanging means therein".
As shown in FIG. 1 showing in a schematic diagram a heating and cooling air conditioner with the above-mentioned combined liquid receiver and liquid divider, the high temperature and high pressure gas refrigerant, after being compressed by a refrigeration compressor unit 1, is cooled and condensed in a condenser 2. The high temperature and high pressure gas refrigerant is thus reduced from its vapor phase to its liquid phase.
The liquid refrigerant, after being condensed in the condenser 2, in turn is introduced into a liquid receiver part 5a provided in the upper section of the combined liquid receiver and liquid divider 5.
The liquid refrigerant in turn is discharged through an outlet 4a provided in the divider wall 5c of the liquid receiver part and, thereafter, introduced into a pressure reducing unit 4 via conduit 4b having a heat exchanging coil 4c. In the pressure reducing unit 4, the refrigerant becomes low temperature and low pressure liquid refrigerant.
At this time, the heat generated in the liquid receiver part of the combined liquid receiver and divider 5 is transferred to a liquid divider part provided 5b in the lower section of the combined liquid receiver and divider 5.
The low temperature and low pressure liquid refrigerant of the pressure reducing unit 4 is, thereafter, introduced into an evaporator 3 where the low temperature and low pressure refrigerant exchanges heat with outside air and evaporates.
The gas refrigerant which was evaporated in the evaporator 3 is introduced into the liquid divider part of the combined liquid receiver and divider 5 via conduit 3a and, thereafter, introduced into the refrigeration compressor unit 1 through a conduit extending from the divider wall 5c to the compressor unit 1. The above procedure is repeated in a cooling operation of the heating and cooling air conditioner.
At this time, there remains refrigerant of the liquid phase after evaporation of the refrigerant in the evaporator 3 and the remaining liquid phase refrigerant is introduced into the liquid divider part 5b of the combined liquid receiver and divider 5.
However, the heat transfer caused by the internal heat exchange between the liquid receiver part and the liquid divider part of the above combined liquid receiver and divider 5 is carried out only at the wall 5c between the liquid receiver part and the liquid divider part. In this regard, the combined liquid receiver and divider 5 can not completely evaporate the remaining liquid phase refrigerant residing in the liquid divider part 5b, thus failing in the prevention of stratified division between compressor oil and the remaining liquid phase refrigerant. This causes a deterioration of operational reliability of the compressor of the heating and cooling air conditioner.